What is hypermobility and is it linked to autism?

Hypermobility means joints that move beyond their normal range - a common trait, not an illness. It is more common in autistic people (UK research, 2022), but this is an association, not a cause.

What hypermobility is

Joint hypermobility means having very flexible joints, what most people call being “double-jointed”. The NHS explains that it comes from differences in collagen, the protein that makes ligaments, leaving those ligaments a little stretchier than usual. It is common, affecting roughly 1 in 4 people, and it shows up most often in children and young people, often easing as they grow. On its own, being bendy is not an illness and needs no treatment.

A GP can measure it using the Beighton score, a simple 9-point check of how far certain joints bend. Most hypermobile children have no problems at all. For a smaller group, very flexible joints come with symptoms such as joint pain or repeated sprains; this sits on a spectrum that runs from hypermobility spectrum disorders through to Ehlers-Danlos syndrome, a group of inherited connective-tissue conditions.

The autism link

Yes, there is a real link, and it has been measured in the UK. A 2022 study from Brighton and Sussex Medical School, led by Dr Jessica Eccles, found that around 51% of neurodivergent participants (people who are autistic, have ADHD or have a tic disorder) had raised joint hypermobility on the Beighton scale, compared with about 20% of the general population. Those participants also reported more pain and more dysautonomia, problems with the body's automatic functions such as feeling dizzy on standing. Researchers think a shared difference in connective tissue may sit underneath both, though that is not yet settled.

What the link does and does not mean

This is an association, not a cause, and it is not part of how autism is diagnosed. Two things follow from that, and they are the points the top US-written results tend to miss:

• Being hypermobile does not mean a child is autistic, and not every autistic child is hypermobile. Flexibility is a trait, not a sign of autism, and it does not change the autism picture either way.
• The reason it is worth knowing is practical, not diagnostic. Hypermobility can come with joint pain, fatigue and dysautonomia that are easy to overlook in a child who is also being assessed for, or living with, autism. Those symptoms are worth flagging to a GP in their own right.

If you are weighing up several overlapping traits, our explainer on the difference between autism and ADHD may help you separate what belongs where.

This page is general information, not clinical or legal advice.